In 2020, the INIT Lab collaborated with the Ruiz HCI lab, in particular lead Ph.D. student author Julia Woodward, on a study to understand how well Fitts’ Law and FFitts’ Law applies to children’s touching behaviors on touchscreen devices. This study ended up being published in a paper entitled “Examining Fitts’ and FFitts’ Law Models for Children’s Pointing Tasks on Touchscreens“, and appeared at the International Conference on Advances Visual Interfaces (AVI’2020), which was held in fall of 2020 as a virtual event. Here is our paper’s abstract:

Fitts’ law has accurately modeled both children’s and adults’ pointing movements, but it is not as precise for modeling movement to small targets. To address this issue, prior work presented FFitts’ law, which is more exact than Fitts’ law for modeling adults’ finger input on touchscreens. Since children’s touch interactions are more variable than adults, it is unclear if FFitts’ law should be applied to children. We conducted a 2D target acquisition task with 54 children (ages 5-10) to examine if FFitts’ law can accurately model children’s touchscreen movement time. We found that Fitts’ law using nominal target widths is more accurate, with a R2 value of 0.93, than FFitts’ law for modeling children’s finger input on touchscreens. Our work contributes new understanding of how to accurately predict children’s finger touch performance on touchscreens.

You can find the camera-ready version of this paper here, which Julia presented remotely during the AVI virtual event in 2020. We are pleased to continue to push the field’s knowledge forward regarding how to recognize and adapt to kids’ specific interaction behaviors.